Battery cell, battery and power utilization device

Abstract

The utility model discloses a battery cell, a battery and a power utilization device. The battery cell comprises an electrode assembly formed by winding a positive electrode layer, a diaphragm layer, a negative electrode layer and a diaphragm layer which are stacked in sequence, a protective layer is wound on the outer surface of the electrode assembly; the protective layer is provided with a transmission channel used for storing electrolyte and / or enabling the electrolyte to permeate into the electrode assembly. According to the invention, electrolyte infiltration ways can be increased, the electrolyte rapidly infiltrates the electrode assembly through the transmission channel on the protective layer, and the infiltration effect of the electrolyte is effectively improved, so that the reliability of the battery cell and the battery is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electrochemical energy storage devices, and in particular to a battery cell, a battery and an electrical device for improving the electrolyte infiltration effect of a lithium-ion battery. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in terminal products such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools.

[0003] In the development of battery technology, in addition to improving battery performance, the reliability of batteries is also an issue that cannot be ignored. If the reliability of batteries cannot be guaranteed, it will directly affect the reliability, use cost and user experience of terminal products. Therefore, how to enhance battery reliability is a technical problem that needs to be solved urgently in battery technology. Summary of the invention

[0004] The object of the present invention is to provide a battery cell, a battery and an electrical device with high reliability.

[0005] In order to achieve the above purpose, this application adopts the following technical applications:

[0006] In a first aspect, the present application provides a battery cell, comprising:

[0007] The electrode assembly is obtained by stacking a positive electrode layer, a separator and a negative electrode layer in sequence, and the outermost side of the electrode assembly is the separator;

[0008] The protective layer is wrapped around the outer circumference of the isolation membrane of the outermost layer of the electrode assembly, and the protective layer is provided with a transmission channel for allowing the electrolyte to pass through.

[0009] In the above technical solution, by opening a transmission channel in the protective layer, it is beneficial to uniformly infiltrate the electrolyte, improve the performance of the battery cell, and thus improve the reliability of the battery cell and the battery.

[0010] In an optional example, the transmission channel is a hollow structure that penetrates the protective layer.

[0011] In the above technical solution, by setting the transmission channel as a hollow structure, the infiltration speed of the electrolyte is further accelerated, the infiltration effect of the electrolyte is improved, thereby improving the performance of the battery cell, thereby improving the reliability of the battery cell and the battery.

[0012] In an optional example, the transmission channel includes at least one of a through hole and a groove.

[0013] In the above technical solution, by setting different types of transmission channels, the wetting requirements of the electrolyte at different positions of the protective layer can be better met, so that the electrolyte infiltration effect is better, thereby improving the performance of the battery cell, thereby improving the reliability of the battery cell and the battery.

[0014] In an optional example, the transmission channel includes a plurality of through holes arranged at intervals; the distance between two adjacent through holes is greater than or equal to 1 mm; and / or the area of ​​the through holes is ≤0.1 square millimeters.

[0015] In the above technical solution, by setting the through holes at intervals, the overall infiltration speed of the electrolyte is accelerated, making the electrolyte infiltration more uniform, thereby improving the performance of the battery cell, thereby improving the reliability of the battery cell and the battery.

[0016] In an optional example, the through-hole electrode assembly is arranged in multiple rows in the width direction, each row includes a plurality of through holes arranged at intervals along the circumference of the electrode assembly, and the plurality of through holes in any two adjacent rows are staggered in the width of the electrode assembly.

[0017] In the above technical solution, by setting it in the width direction in an interval and staggered manner, the infiltration speed of the electrolyte can be further accelerated, making the electrolyte infiltration effect more uniform, thereby improving the performance of the battery cell.

[0018] In an optional example, the transmission channel includes a plurality of grooves arranged at intervals; the distance between two adjacent grooves is greater than or equal to 5 mm; and / or the width of each groove is less than or equal to 1 mm.

[0019] In the above technical solution, by setting the transmission channel intervals as grooves and setting them at a specific distance, the wetting requirements of the electrolyte can be better met, the wetting effect can be improved, and thus the performance of the battery cell can be improved.

[0020] In an optional example, the groove extends along the circumference of the electrode assembly, or the groove extends along the width of the electrode assembly;

[0021] And a plurality of grooves are arranged in parallel.

[0022] In the above technical solution, by arranging the grooves in a specific manner, the wetting requirements of the electrolyte can be better met, the wetting effect can be improved, and thus the performance of the battery cell can be improved.

[0023] In an optional example, the protective layer includes: an insulating material layer and a glue layer, and the insulating material layer is attached to the outer surface of the electrode assembly through the glue layer.

[0024] In the above technical solution, by providing the insulating material layer and the glue layer, not only the insulation requirements inside the battery cell are met, but also the fixation between the protective layer and the electrode assembly is achieved, further improving the reliability of the battery cell.

[0025] In an optional example, the thickness of the protective layer is 30 micrometers to 180 micrometers.

[0026] In the above technical solution, by setting the above thickness range, not only the thickness requirement of protecting the electrode assembly is met, but also the space occupied inside the shell is reduced, so that the capacity of the battery cell is increased.

[0027] In an optional example, along the direction of the central axis of the electrode assembly, the length of the electrode assembly is greater than or equal to the length of the protective layer; and / or, along the circumference of the electrode assembly, the length of the protective layer is less than the circumference of the electrode assembly.

[0028] In the above technical solution, by setting the length of the protective layer, the volume of the electrode assembly after the protective layer wraps is reduced, thereby improving the internal capacity of the battery.

[0029] In an optional example, the electrode assembly is formed by winding a positive electrode layer, a separator and a negative electrode layer stacked in sequence.

[0030] In the above technical solution, by setting the electrode assembly as an electrode assembly, the protective layer is easy to fix and wrap the electrode assembly, thereby improving the safety of the battery cell.

[0031] In an optional example, the electrode assembly includes at least two bending portions, and the transmission channel is arranged on a protective layer corresponding to and wrapping at least one bending portion.

[0032] In the above technical solution, the transmission channels are arranged at all the bending parts, which can further achieve full contact with the electrolyte and better meet the infiltration requirements of the electrolyte.

[0033] In an optional example, a transmission channel is provided on the protective layer corresponding to each bending portion.

[0034] In the above technical solution, the transmission channels are arranged at all the bending parts, which can further achieve full contact with the electrolyte and better meet the infiltration requirements of the electrolyte.

[0035] In an optional example, the starting wrapping position and the ending wrapping position of the protective layer are both located at the bending portion.

[0036] In the above technical solution, the protective layer can not only better protect the electrode assembly, but also reduce the thickness of the electrode assembly, further improving the internal capacity of the battery cell.

[0037] In a second aspect, the present application provides a battery, including a box and a battery cell as described above arranged in the box.

[0038] In the above technical solution, the battery is equipped with the above-mentioned battery cell, which improves the internal insulation performance of the battery, increases the infiltration speed of the electrolyte, and increases the capacity inside the battery cell.

[0039] In a third aspect, an electrical device comprises the above battery. In the above technical solution, the safety and performance of the electrical device are improved by using the above battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical application in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0042] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0043] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0044] Figure 4 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0045] Figure 5 Schematic diagram of the partial structure of the battery cell provided in some embodiments of the present application Figure 1 ;

[0046] Figure 6 Schematic diagram of the partial structure of the battery cell provided in some embodiments of the present application Figure 2 .

[0047] Figure Number:

[0048] 1. Electrode assembly; 2. Positive electrode layer; 3. Diaphragm layer; 4. Negative electrode layer; 5. Upper corner of electrode assembly; 6. Protective layer; 7. Transmission channel; 8. Lower corner of electrode assembly; 01-Vehicle; 20-Controller; 30-Motor; 101, Box; 102, Battery cell; 1012, First part; 1011, Second part. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0051] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", and "attachment" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0054] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0055] The term "plurality" used in this application refers to more than two (including two).

[0056] In the present application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. The battery cell is generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0057] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the cell.

[0058] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet (for example, deintercalation) to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode ear. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode ear. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current is passed without melting, the number of positive electrode ears is multiple and stacked together, and the number of negative electrode ears is multiple and stacked together. The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0059] The development of battery technology must consider many design factors at the same time, such as performance parameters such as energy density, cycle life, discharge capacity, charge and discharge rate, and battery reliability. In the prior art, the electrolyte infiltration degree of the electrode assembly directly affects the reliability of the electrode assembly and the battery. Therefore, in order to ensure the reliability of the battery, mechanical decarbonization or inter-electrode coating or laser decarbonization is usually required to mechanically process the positive and negative electrode structures to form grooves on the surface of the electrode sheet of the electrode assembly. This will damage the electrode structure of the lithium-ion battery, resulting in a problem of reduced coating weight of the active material on the electrode, seriously affecting the conductivity of the electrode, and increasing the impedance of the electrode sheet, which ultimately leads to a serious decline in the performance of the battery cell.

[0060] Therefore, based on the current situation, the present application provides a battery cell, in which a protective layer is arranged outside the electrode assembly of the battery cell. The protective layer is wrapped around the outer circumference of the isolation membrane of the outermost layer of the electrode assembly, and the protective layer is provided with a transmission channel, which serves as a transmission path for the electrolyte. Through the transmission channel, the electrode assembly increases the contact area between the electrolyte and the electrode assembly, improves the infiltration speed and uniformity of the electrolyte, and effectively improves the electrolyte infiltration effect of the battery, thereby improving the reliability of the battery.

[0061] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0062] For the convenience of explanation, the following embodiments are described by taking a vehicle as an example of an electric device, and a battery cell proposed in the present application is described in detail.

[0063] Figure 1 This is a schematic diagram of the structure of the vehicle 01 provided in some embodiments of the present application. Figure 1 The vehicle 01 is provided with a battery 10 inside. The battery 10 can be provided at the bottom, head, or tail of the vehicle 01, or even mounted on the top or side of the vehicle 01. The battery 10 can be used to power the vehicle 01, for example, the battery 10 can be used as an operating power source for the vehicle 01.

[0064] The vehicle 01 may also include a controller 20 and a motor 30, wherein the controller 20 is used to control the battery 10 to supply power to the motor 30, for example, for starting, navigating, and operating power requirements of the vehicle 01. Of course, in some embodiments of the present application, the battery 10 may not only be used as an operating power source for the vehicle 01, but may also be used as a driving power source for the vehicle 01, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 01.

[0065] Figure 2 An exploded view of a battery 10 provided in some embodiments of the present application; Figure 3 Schematic diagram of the local structure of the battery 10 provided in some embodiments of the present application Figure 1 ; Figure 4 Schematic diagram of the local structure of the battery 10 provided in some embodiments of the present application Figure 2 Please refer to Figures 2 to 4 The battery 10 includes a housing 101 and a battery cell 102 , wherein the housing 101 is used to accommodate the battery cell 102 .

[0066] Among them, the box body 101 is a component for accommodating the battery cell 102. The box body 101 provides a storage space for the battery cell 102 to ensure the reliability, stability and reliability of the battery cell 102. The box body 101 can adopt a variety of structures. In some embodiments, the box body 101 can include a first part 1011 and a second part 1012. The first part 1011 and the second part 1012 are covered, buckled or stably matched in other ways to define a storage space for accommodating the battery cell 102. At the same time, the first part 1011 and the second part 1012 can be in a variety of shapes, such as a cuboid, a cylinder, etc. The first part 1011 can be a hollow structure with one side open, and the second part 1012 can also be a hollow structure with one side open. The open side of the second part 1012 covers the open side of the first part 1011, so as to form a box body 101 with a storage space. Alternatively, the first part 1011 may be a hollow structure with one side open, and the second part 1012 may be a plate-like structure, and the second part 1012 may cover the open side of the first part 1011, thereby forming a box body 101 with a receiving space. The first part 1011 and the second part 1012 may be sealed by a sealing element, which may be a sealing ring, a sealant, or the like.

[0067] Please refer again Figure 2In the battery 10, the number of the battery cells 102 can be one or more. If there are multiple battery cells 102, the multiple battery cells 102 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 102 are both connected in series and in parallel. Multiple battery cells 102 can be connected in series, in parallel, or in mixed connection to form a battery module, and the multiple battery modules can be connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 101. All battery cells 102 can also be directly connected in series, in parallel, or in mixed connection, and then the whole formed by all battery cells 102 is accommodated in the box 101.

[0068] In some embodiments, the battery 10 may further include a busbar, through which the multiple cells 102 may be electrically connected to each other, so as to realize series connection, parallel connection or mixed connection of the multiple cells 102. The busbar may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0069] See also Figure 3 The battery cell 102 provided in the present application includes: a shell, an electrode assembly, an electrolyte and a protective layer.

[0070] The housing is a component for containing the electrode assembly 1 and the electrolyte (not shown).

[0071] The electrode assembly 1 can be obtained by stacking or winding the positive electrode layer 2, the separator 3 and the negative electrode layer 4 in sequence, and the outermost side of the electrode assembly 1 is the separator 3. The protective layer 6 is wrapped around the outer circumference of the separator 3 of the outermost layer of the electrode assembly 1, and the protective layer 6 is provided with a transmission channel 7 for the electrolyte to pass through. Specifically, the electrode assembly 1 can be formed by winding the positive electrode layer 2, the separator 3 and the negative electrode layer 4 stacked in sequence. Another separator layer 3 can be wound on the outside of the electrode assembly 1.

[0072] In the present application, the battery cell 102 is not limited to one positive electrode layer 2 and one negative electrode layer 4, and may include multiple positive electrode layers 2 and multiple negative electrode layers 4, multiple positive electrode layers 2 and multiple negative electrode layers 4, arranged in a manner of alternating stacking of the positive electrode layers 2 and the negative electrode layers 4, and a separator layer 3 is provided between the positive electrode layers 2 and the negative electrode layers 4. In one embodiment, the positive electrode layer 2 is composed of a current collector coated with a positive electrode active material and a positive electrode tab; the negative electrode layer 4 is composed of a current collector coated with a negative electrode active material and a negative electrode tab. The electrode tab is arranged parallel to the winding direction of the electrode assembly 1.

[0073] In the present application, in order to prevent the electrode assembly 1 from dispersing, a protective layer 6 can be added to the outer surface of the electrode assembly 1. The protective layer 6 is provided with a transmission channel 7 for storing electrolyte and / or allowing the electrolyte to penetrate into the electrode assembly 1. In addition to being able to restrain the electrode assembly 1, the protective layer 6 can also allow the electrolyte to quickly infiltrate the upper corner 5 of the electrode assembly and the lower corner 8 of the electrode assembly, thereby improving the infiltration effect of the electrolyte, increasing the contact area between the electrolyte and the electrode assembly 1, and reducing the infiltration path of the electrolyte. In addition, when the protective layer 6 is used as the restraining structure of the electrode assembly 1, the additional isolation film added to the outer surface of the electrode assembly 1 during conventional processing can be reduced, thereby improving the energy density of the electrode assembly 1.

[0074] Specifically, in order to increase the transmission speed of the electrolyte through the protective layer 6, the transmission channel 7 can be set as a hollow structure that penetrates the protective layer 6, so that the protective layer 6 can store or transmit more electrolyte within the same area.

[0075] In one example, if Figure 3 and Figure 5 As shown, the transmission channel 7 can adopt multiple through holes; multiple through holes are arranged on the protective layer 6 in an array. The through holes are arranged in multiple rows along the width direction of the electrode assembly, and each row includes multiple through holes arranged at intervals along the circumference of the electrode assembly, and the multiple through holes of any two adjacent rows are staggered in the width of the electrode assembly. The electrolyte is transmitted to the electrode assembly 1 along the through holes in a three-dimensional infiltration and diffusion manner through multiple through holes, thereby quickly increasing the contact area between the electrolyte and the electrode assembly 1, shortening the electrolyte infiltration path, and increasing the electrolyte infiltration speed. In addition, in order to ensure the infiltration effect of the electrolyte, the distance between adjacent through holes is greater than or equal to 1 mm, and / or the area of ​​the through hole is less than or equal to 0.1 square millimeter. For example, the spacing between adjacent through holes is 1 mm, 3 mm, 5 mm, 8 mm or 10 mm, etc. The area of ​​the through hole can be 0.02 square millimeters, 0.05 square millimeters, 0.08 square millimeters, 0.1 square millimeters, etc.

[0076] In another example, if Figure 4 and Figure 6As shown, the transmission channel 7 can adopt multiple channels; multiple channels are arranged on the protective layer 6 in a horizontal or vertical parallel manner. The grooves extend along the circumference of the electrode assembly, or the grooves extend along the width of the electrode assembly; and multiple grooves are arranged in parallel. The electrolyte is transmitted to the electrode assembly 1 along multiple channels, and penetrates and diffuses on the electrode assembly 1, thereby quickly increasing the contact area between the electrolyte and the electrode assembly 1, shortening the electrolyte infiltration path, and increasing the electrolyte infiltration speed. In addition, in order to ensure the wetting effect of the electrolyte, the distance between adjacent channels must be greater than or equal to 5 mm, and / or the width of each groove is less than or equal to 1 mm. For example, the spacing between adjacent through holes can be 5 mm, 8 mm or 10 mm, etc. The width of the groove can be 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, etc.

[0077] In the present application, the protective layer 6 needs to play a certain protective role on the electrode assembly 1 to prevent foreign objects on the production line from piercing the protective layer 6. At the same time, the thickness of the protective layer 6 cannot be too thick, which will affect the installation of the electrode assembly 1 into the shell.

[0078] Specifically, the protective layer 6 can be an insulating material layer made of insulating material, and a transmission channel 7 is opened on the insulating material layer. Then, the insulating material layer is applied to the outer surface of the electrode assembly 1 using a glue layer. The thickness of the protective layer 6 can be controlled in the range of 30 microns to 180 microns.

[0079] In one example, the protective layer 6 may be made of an insulating adhesive tape with adhesiveness on one side, and the adhesive side of the insulating adhesive tape is bonded to the outer surface of the electrode assembly 1. The thickness of the protective layer 6 is 50 micrometers.

[0080] In another example, the protective layer 6 can be an insulating PET (polyethylene terephthalate) substrate, and then the PET substrate is attached to the outer surface of the electrode assembly 1 using a pressure-sensitive adhesive. The total thickness of the PET substrate and the pressure-sensitive adhesive is 150 microns.

[0081] In the present application, the length of the protective layer 6 along the central axis of the electrode assembly 1 needs to be controlled within the range of the upper corner 5 of the electrode assembly and the lower corner 8 of the electrode assembly. Specifically, along the central axis of the electrode assembly 1, the length of the electrode assembly 1 is greater than or equal to the length of the protective layer 6.

[0082] In one example, if Figure 1 As shown, the length of the protective layer 6 along the central axis direction of the electrode assembly 1 does not exceed the upper corner and the lower corner of the electrode assembly 1.

[0083] In the present application, considering the subsequent expansion problem of the electrode assembly 1, it is necessary to control the length of the protective layer 6 along the circumference of the electrode assembly 1. Specifically, along the circumference of the electrode assembly 1, the length of the protective layer 6 is less than the circumference of the electrode assembly 1.

[0084] In one example, if Figure 1 As shown, when the protective layer 6 is wrapped around the electrode assembly 1, its initial position cannot overlap, but can abut or reserve a small gap to reserve space for the electrode assembly 1 to expand.

[0085] In the present application, at least two bends may be provided on the electrode assembly, and the transmission channel is provided on the protective layer 6 that wraps any bend. The transmission channel is provided on the protective layer 6 that wraps all bends. The starting wrapping position and the ending wrapping position of the protective layer 6 are provided on the bend.

[0086] When preparing the battery cell 102 of the present application, the positive electrode layer 2, the diaphragm layer 3, the negative electrode layer 4 and the diaphragm layer 3 are first stacked and wound on the winding device in order. Using the winding device, the positive electrode layer 2, the diaphragm layer 3, the negative electrode layer 4 and the diaphragm layer 3 are wound into the electrode assembly 1 according to the predetermined speed and tension. Then, a pressure-sensitive adhesive is applied to one side of the PET substrate with the transmission channel 7, and the PET substrate is wound on the outer surface of the electrode assembly 1 using the winding device, so as to restrain the electrode assembly 1 while ensuring the adhesion between the PET substrate and the outer surface of the electrode assembly 1. Subsequently, when the electrolyte is infiltrated, the electrolyte can contact the electrode assembly 1 through the transmission channel 7, and quickly climb to the corner of the electrode assembly 1, thereby achieving the purpose of quickly and effectively infiltrating the electrode assembly 1. At the same time, a certain amount of electrolyte can be retained in the transmission channel 7 after the electrode assembly 1 is infiltrated, so that the infiltration effect of the electrode assembly 1 is better.

[0087] Based on the above battery cell 102, the present application further discloses a battery, which includes a box 101 and the above battery cell 102 disposed in the box 101. Since the battery includes the above battery cell 102, the battery also has the advantage of high reliability.

[0088] Based on the above battery cell 102, the present application further discloses an electric device, which includes the above battery. Therefore, the electric device also has the advantage of high reliability.

[0089] The present application increases the electrolyte infiltration pathway by adding a protective layer 6 having a transmission channel 7 on the outside of the electrode assembly 1. The electrolyte quickly infiltrates the electrode assembly 1 through the transmission channel 7 on the protective layer 6, thereby improving the electrolyte infiltration effect and effectively avoiding the problem of poor infiltration at the corners of the electrode assembly 1.

[0090] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical application of the present invention are still within the protection scope of the present invention.

Claims

1. A battery cell, characterized in that: include: The electrode assembly is obtained by stacking a positive electrode layer, a separator and a negative electrode layer in sequence, and the outermost side of the electrode assembly is a separator; The protective layer is wrapped around the outer circumference of the outermost isolation film of the electrode assembly, and the protective layer is provided with a transmission channel, and the transmission channel is used for the electrolyte to pass through.

2. The battery cell according to claim 1, characterized in that: The transmission channel is a hollow structure that penetrates the protective layer.

3. The battery cell according to claim 1, characterized in that: The transmission channel includes at least one of a through hole and a groove.

4. The battery cell according to claim 3, characterized in that: The transmission channel includes a plurality of through holes arranged at intervals; the distance between two adjacent through holes is greater than or equal to 1 mm; and / or the area of ​​the through holes is less than or equal to 0.1 square millimeters.

5. The battery cell according to claim 4, characterized in that: The through holes are arranged in multiple rows along the width direction of the electrode assembly, each row includes multiple through holes arranged at intervals along the circumference of the electrode assembly, and the multiple through holes in any two adjacent rows are staggered across the width of the electrode assembly.

6. The battery cell according to claim 3, characterized in that: The transmission channel includes a plurality of grooves arranged at intervals; the distance between two adjacent grooves is greater than or equal to 5 mm; and / or the width of each groove is less than or equal to 1 mm.

7. The battery cell according to claim 6, characterized in that: The groove extends along the circumference of the electrode assembly, or the groove extends along the width of the electrode assembly; And a plurality of the grooves are arranged in parallel.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The protective layer includes: an insulating material layer and a glue layer, and the insulating material layer is attached to the outer surface of the electrode assembly through the glue layer.

9. The battery cell according to claim 8, characterized in that: The thickness of the protective layer is 30 micrometers to 180 micrometers.

10. The battery cell according to any one of claims 1 to 7, characterized in that: Along the direction of the central axis of the electrode assembly, the length of the electrode assembly is greater than or equal to the length of the protective layer; and / or, along the circumference of the electrode assembly, the length of the protective layer is less than the circumference of the electrode assembly.

11. The battery cell according to any one of claims 1 to 7, characterized in that: The electrode assembly is formed by winding a positive electrode layer, a separator and a negative electrode layer stacked in sequence.

12. The battery cell according to claim 11, characterized in that: The electrode assembly includes at least two bending portions, and the transmission channel is arranged on the protective layer corresponding to and wrapping at least one of the bending portions.

13. The battery cell according to claim 12, characterized in that: The transmission channel is provided on the protection layer corresponding to each bending portion.

14. The battery cell according to claim 13, characterized in that: The starting wrapping position and the ending wrapping position of the protective layer are both located on the bending portion.

15. A battery, characterized in that: It comprises a box body and the battery cell according to any one of claims 1 to 14 arranged in the box body.

16. An electrical device, characterized in that: Comprising the battery of claim 15.

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